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THE DISTRIBUTOR’S LINK
Anthony Di Maio
Anthony E. Di Maio attended Wentworth Institute and Northeastern University. In 1962 he
started working with Blind Fasteners as Vice-President of Engineering & Manufacturing for two
blind rivet manufacturers. He has been Chairman of the Technical Committee of the Industrial
Fasteners Institute (IFI) and is still involved in the writing of IFI specifications. In 1991, he
started ADM Engineering and is working with Fastener Manufacturers developing new fasteners
and special machinery. He can be reached at ADM Engineering, 6 Hermon Ave., Haverhill, MA
01832; phone and fax 978-521-0277; e-mail: tdimaio@verizon.net.
SELECTING THE CORRECT BLIND RIVET
The question that I am asked many times is, “Which
blind rivet should I use for my application?” I first review
their application and then we discuss the following
topics and we determent the proper blind rivet for the
application. We discuss the following subjects to make
the correct determination as to which blind rivet is the
correct one to use.
[1] Tensile & shear requirements for the application
[2] Environment
[3] Work thickness
[4] Proper blind rivet grip range
[5] Material to be riveted
[6] Hole size
Tensile & Shear Requirements
First and foremost the blind rivet is a fastener and
must have the proper tensile and shear values to securely
fasten the components together. One or more blind
rivets can be used to meet the tensile and shear value
requirements. When we have established how many blind
rivets we are going to use for a tight assembly, we then
look at the tensile and shear values in the manufacturer’s
catalogue and we now know the various diameters and
alloys of the blind rivets we can choose from.
Environment
Is the application indoors or outdoors, near a
corrosive environment, used in a food application? Let us
discuss these four environments.
used.
¤ Indoors - Any alloy or combination of alloys can be
¤ Outdoors - Cannot use steel mandrels. Even if the
CONTRIBUTOR ARTICLE
mandrel is plated, it will rust where the mandrel breaks
when setting the blind rivet. Aluminum and stainless steel
would be the alloy to use.
¤ Corrosive Environment - Stainless steel would
be a good choose, depending on how severe the
environment is, aluminum may also be used.
¤ Food Application - Stainless steel must be used.
Work Thickness
The work thickness will determine the length of blind
rivet needed for the application. All manufacturers list
the grip range of their blind rivets. Do not use the shank
length of the blind rivet body as the grip range length of
the blind rivet. Work thickness or grip range is the only
way to determine which length blind rivet you need. If the
grip range is not factored to establish blind rivet length,
two occurrences will happen, over-grip and under-grip.
¤ Over-Grip
FIGURE 1 - RIVET BODY LENGTH IS TOO SHORT
TOO SHORT
When a blind rivet is used in a grip range or work
thickness that is greater than the maximum specification
of that blind rivet, the mandrel head will fall out after
setting the blind rivet. This occurs because there is not
enough rivet body length to capture and lock the mandrel
head when setting the blind rivet in the work piece.
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